Pitman rod connection for radial cylinder engines



1935- L. CHEVROLET PITMAN ROD CONNECTION FOR RADIAL CYLINDER ENGINESFiled May 16, 1932 IIIIIIIIIIIIII svwc/wio [ad/J Chevrolet.

Patented Feb. 19, 1935 UNITED. sTATas This invention relates to certainnew-and useful improvements in pitman rod connections for radialcylinder engines H Extreme difiiculty has been encountered in makingpitman rod connections in this; type of ngine owing'to thefact that theangular or articulatedpositions of the several pitmans must be uniformthroughout the operations of the engine. -In=an attempt to-accomplishthis, there are illustrations in the prior art suggesting the.

use-of a master :pitman rodwhich encircles the crankofthe'engine-shaftand-to this encircling section of the master pitman theauxiliary pitmans are -pivotally attached. In such cases, hOW1 I ever,thefiring point intheseveralcylinders: does not coincide and, therefore;is not evenly timed; nor'is the stroke and angularity of the severalpitmans balanced and uniform.; Itlhas also. been foundthat the pistonwhich is-connected to-the master pitman is subjected toall; of "thesidethrusts resulting fro1n=the explosion or working strokes of all; ofthe-other cylinders. Further, in making these 'so-called masterpitmans,- expert and necessarily expensive machiningoperations ,must bemadeinproviding the bearing openings in which'the auxiliary pitmans aremounted.-

It is. therefore,;.the basic'object of the-present invention to providea structure wherein all of the pitman, rods are of a likQ: constructionand connected' to the crank shaft of theengine at points concentric tothe'crank-shaft'sothat all the pitmans will have auniform angularity ;ofmovement or articulation; v

Another object of the invention is-the provision of aconstructionwhereinthe firing Point of the several cylinders-may beevenly timed which the operation of the'engine'." q

A still further object of the present invention resides in thecoordination of the movements of; two of the pitman rods which resultsin the perfect angularity .oriarticulation of the entire series ofconnectedpitmans; with an even distribution of the side-thrusts from theworking results in a moreibalanced andsmooth action in strokes of alLofthe cylinders to a plurality of pistons instead of one.

Other objects and aims of the invention will more readily'presentthemselves to those skilled in this art when the following specificationis read in connection with the attached drawing wherein I haveillustrated in a general way the application of my principle. It will,of course, be fully understood that certain changes and variations maybe resorted to without sacrificing any of the spirit of the presentinvention. The scope of protectionsougnt will appear-in the appendedclaims. n h d a n lik. na t eq d t b similar letters.ofrreferencewhereim 1 :Fig. 1'; is a side elevation of -the improved pitmanrodrconnectionto thecrank shaft of an 5 engine, 'said crank shaft beingshownin section; Fig. .2 is a cross-sectional Niew taken' on'line .-2-0fF .1; and q ;Eig.,-3 is also aecross -sectional view taken on Referrin-more indetail to, :the attached drawe ns .n, icate th p ank ab r on anen ne shaft i and jo which it desirous to I attach. the inner i ends orthe several :pitman rods. Mounted on;the;-crank 1 a channel shaped ring2 5 within'the'bore of which-is secured asplit bushins li -3. Theupstanding walls of the channel ring 2 are providedwith a plurality ofequally spaced and circularly arrangedapertures 4, the apertures 4'inone walh-being aligned with those of the opposite wall to receive thecross bolts or knuckle pins 5. These pins 5 are securely retained intheir proper position by 1 any suitable 1 nd anchoring. means and in thedrawing the ;sug-. gested usefof athreaded;nut 6 with a locking keyor;cotter;;7:is;merely illustrativeof oneiform of anchoring .means.

.Theinnen; end .-8 oi each pitman! snuglyfitsi withinthephannel ring ,2;and ispivota-lly mount- 1 ed onone'iof the ;cross"bolts;or knuckle :pins5.

Any suitablafor'm of bearing or sleeve 'lo'may be usedatthepivotalpointof the connections of the pitmans 9,120 ;the cross boltor knuckle'pins :5. V ,severalyofi the -knucklepins ;5. are of asufficient --length .to permitthe assemblage of gear Sectors:thereon=and'"to.'better illustrate this; attention is directed to Figs.2 and 3. InFig. .2 the;gear jsectors; 11 are-capable of free pivotalmotion onEthe .ends of the pinsjswhile in Fig. 3. thegear 121's rkeyed.as1at13 to-the knuckle pin5 so asgtooscillate therewith; Also in Fig.Spit willabeinoted that thewinner end of, the pitman. 9 is keyed asat 14to the knuckle pin 5 so as to transmit the oscillatory or turningmovements of the pitman 9 to the pin 5.

As is clearly shown in Fig. 1, several of the sector gears 11 are soarranged as to intermesh and thereby transmit the movement which isimplied thereto by either of the gears 12 which are at the terminal endsof the train of gears. In this figure there is shown'a ten cylinderconstruction with the gearing arranged between six ofthe pitmans, fourbeing merely idlers and the end ones being keyed to the knuckle pins forpositive motion therewith. It will be clearly un- 5 to the crank shaft.

derstood that the number of cylinders herein shown is merelyillustrative and should not be construed in a limiting sense as thisgeneral principle can be employed in radial engine constructionsregardless of the number of cylinders just so long as'the gear train isassociated with the two opposite pitmans employed and has the propernumber of gears to reverse the motion.

In order that the moving parts may be suitably lubricated, oil underpressure is-housed within the crank shaft reservoir 15 which is providedwith an outlet duct 16. The bushing 33 has a series of transversepassages 17 which are. in registry with the branched ducts 18 leading tothe bearing point or points of the knuckle pins 5 in the ring member 2.Furthermore as shown in Fig. 2 the knuckle pin may be providedwith achannel or duct 19 to properly distribute the lubricant to the bushingmember and the pivotally supported gear 11. The oil being under pressurein the reservoir will be forced through the outlet duct 16 and into thepassages 17 in the bushing'when' the duct 16 is brought into successiveregistry with the several passages 17 and a sumcient amount of lubricantwill be supplied at" the various needed points by the branched ducts18"and' 19.

In assembling the construction shown in the attached drawing the channelring 2 is-first mounted on the crank shaft of the engine. Then the innerends 8 of the several pitmans 9 are pivotally associated with said ringby the knuckle pins 5. The gear segments 11 are then arranged on thepins so as to intermesh through their full range of movement and the endgears 12 are keyed to their respective pins 5. The'ring 2 is, therefore,effectively locked against any relative shifting or turning movement onthe crank shaft so that all of the pitmans are set so as'to have theirproper angular movements with reference What I claim is: r r

1. A pitman rod assemblage for radial engines, comprising acrankshaft,"a'ring mounted thereon, knuckle pins carried by the ring, pitmanrods mounted on the pins, two 'of'said pitman rods beingkeyed to theirknuckle pins, and means for transmittingthe pivotal movements of one Iof said keyed pins to the other keyed pin.

2; A pitman rod assemblage for radial engines, comprising a crank shaft,a ring mounted thereon, knuckle pins carried by the ring, pitman rodsmounted.- on the pins, two of the pitmans oppo-' sitely'disposed beingkeyed to their knuckle pins and means for" transmitting the pivotalmovements of one of 'said keyed pins tothe-other keyed pin. V r

' 3. A pitman rod assemblage for radial engines, comprising'a' crankshaft, a ring mounted thereon, knuckle pins carried by the ring, pitmanrods mounted on the pins, two of saidpitman rods being keyed to theirknuckle pins,and a posito the other keyed pin.

tively actuatingmeans for transmitting the pivotal movements of one ofsaid keyed pins to the 7 other keyed pin.

4. A pitman rod assemblage for radial engines, comprising a crank shaft,a ring mounted thereon, knuckle pins carried by the ring, pitman rodsmounted on the pins, two of said pitman rods being keyed to theirknuckle pins, a gear amxed to each of said keyed knuckle pins and aseries ofv intermeshed gear segments for transmitting the pivotalmovements of one of said keyed pins 5. .A pitman rod assemblage forradial engines, comprising a crank shaft, a ring mounted thereon,knuckle pins carried by the ring, pitman rods mounted on the pins, twoof said pitman rods being keyed to their knuckle pins, a. gear aflixedto each of said keyed knuckle pins and a series of intermeshed gearsegments pivotally support- I ed on the intermediate knuckle pinsfor'transmitting the'pivot'almovements of one of said keyed pins to theother keyed pin;

6. A pitman rod assemblage for radial engines? comprising a crank shaft,a ring mounted thereon, knuckle pins carried by the ring, pitman rodsmounted on" the pins, two of said pitmanrods being keyed to theirknuckle pins, and an intermeshing gear train associated with themajority of the knuckle pins with the end gears affixed tosaid-keyed'knuckle pins. m V 1 7. A pitman" rod as'semblagefor radialengine s,

comprising a crank shaft, aring mounted thereffi on, knuckle'pinscarried by the ring, pitman rods;

mounted on the pins, two of said pitman rods being keyed to theirknuckle pins, and means for coordinating the angular movements of saidtwo I 8; A pitman rod assemblage for radial engines,"

COmpfiSmg a'cmnk S a n I shan d'rm member mounted thereon,-knuckle pin'scarried bythe ring member, a series of pitman rods having their innerends positioned-within the channel and secured tosaid'knuckle pins, andmeans for transmitting the pivotal motion of one knuckle pin to anopp'osing-knuckle-pin. W

9. A pitman rod assemblage for' radial engines, comprising-a crankshaft, a ring mounted thereon, knuckle pin'sfcarried by the ring, pitmanrods I mounted on the pins, a plurality of said pitman rods being keyedto their knuckle pins, and'inter-'- connecting means between the keyedknuckle pins for coordinating'their pivotal movements.

10. A'pitman rod assemblage for 'r'adial en-' gines, comprising acrahkshaftfa ring mounted thereon, aseries of pitman rods each having at itsinner end-a knuckle pin'for pivotal attach- .ment to said ring, aplur'alitypf said pitman rods being keyed to their-knuckle pins, and in!terconnectin'g means between the keyed knuckle I pins for coordinatingtheir pivotal movements Lows CHEVROLET.

